Internal combustion engine



June 15, 1965 c. L. GAHAGAN INTERNAL COMBUSTION ENGINE -2 Sheets-Sheet I Filed Feb. 14, 1963 INVENTOR. CHARLES L. 64/1464 M,

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A Horneys June 15, 1965 c. L. GAHAGAN INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 2 Filed Feb. 14, 1963 INVENTOR. CHARLES L. GAHAGA/V Arlomeys United States Patent T 3,188,805 INTERNAL CGMBUSTION ENGINE Charles L. Gahagan, 122 Talbot Ave, Greensburg, Pa. Filed Feb. 14, 1963, Ser. No. 258,393 Ill Claims. (Cl. ell-35.6)

This invention relates to internal combustion engines and is for a reciprocating piston type of engine having opposed combustion chambers.

The engine of the present invention is especially designed for use where the power is delivered through the thrust or jet effect produced from the high velocity discharge of heated gases, but its utility, as will hereinafter appear, is not confined to such use. Utilized as a so-called jet engine, however, it develops a high ratio of power per pound of metal and has few moving parts. In the following description therefore it will be described by way of illustration principally for use as a jet or direct fluid thrust type of engine and without excluding other fields of utility.

The engine in its simplest form has a single cylinder with exhaust ports partway about the periphery midway between its ends. A cylinder head at each end supports one or more glow plugs for igniting fuel, a fuel inlet nozzle that continuously sprays fuel into the cylinder, and an inwardly-opening check valve for the admission of air.

The piston is between the two combustion heads and moves back and forth a distance sufficient only to travel completely past the exhaust ports in each direction. While it will operate from an external air compressor, I prefer that it generate its own air pressure by having the piston carried on a straight rod that passes with a sliding fit through each cylinder head into an extension of the cylinder at each end, each end of the rod having a piston. Each end of the extension is closed with a compressor head having an inwardly-opening check valve, and a passage with a check valve opening toward the nearest cylinder head transfers air from the outer end of respective cylinder extensions to the inner one. Thus, as the piston moves away from one of the cylinder heads, the piston in the cylinder extension pushes air on one side into the combustion chamber and draws in air on its other side.

Once the engine is started, the piston in the main cylinder is driven back and forth at high speed, speeds which are indicated to be of the order of many thousand cycles per minute, with the exhaust gases in effectively continuous volume being pushed out the exhaust port. Collected into a properly contoured tube or after-burner, the

, combustion gases are expelled at high velocity. Where the power is to be utilized otherwise, the piston rod may be extended beyond one of the air compressor heads to operate a reciprocable tool or the like.

An object of the invention is to provide a unique engine of simple construction that has few moving parts.

A further object of the invention is to provide an engine that has a high power-to-weight ratio.

A further object of the invention is to provide an engine that may be used to generate a large volume of high velocity gases capable of generatin" a thrust and adaptable for use where turbo-jets are not practical.

A further object is to provide an engine of this type which is easily assembled and taken apart.

These and other objects and advantages are secured by my invention, which may be more fully understood by reference to the accompanying drawings, in which:

FIG. 1 is a small scale perspective elevation of the engine on a scale indicating its overall appearance;

FIG. 2 is a longitudinal section through the engine;

FIG. 3 is a transverse section in the plane of line III-III of FIG. 2;

FIG. 4 is a transverse section in the plane of line IV IV of FIG. 3;

Patented June 15, 1965 FIG. 5 is a schematic view of the fundamentals of the engine; and

FIG. 6 is a fragmentary view of one end of the engine showing the piston rod extending at one end for operating a reciprocating tool. I

Referring first to FIG. 5, the engine comprises preferably a cylinder 2 with a uniform bore. Spaced equal distances from the middle of the cylinder are similar confronting combustion chamber end walls or cylinder heads 3. The piston 4 is in the space between these heads and moves first toward one and then the other. It is fixed on a central axially-extending rod 5 that passes through each of the two heads and has aircompressing pistons 6 at each end thereof. Each end of the cylinder is closed by an end wall 7, which I term compressor heads. The exhaust port from the combustion chamber is provided by a series of holes 8 extending partway around the periphery midway between the ends of the cylinder, and the travel of the piston is to one side and then 'the other of the exhaust ports. In an engine which I have built of a size to be used at the outer end of a helicopter rotor blade the cylinder is approximately twelve inches in overall length, the diameter about eight inches, and the piston travel is about two inches. These dimensions are merely illustrative.

There is a check valve 9 in each combustion chamber or cylinder head opening toward the central piston. There is a similar check valve 10 in each compressor piston 6 and a similar check valve 11 in each compressor head, all opening in the same direction.

The engine thus has two combustion chambers and two compressors so that it is entirely symmetrical and balanced. As will hereafter appear, fuel is fed continuously through a minute spray into each combustion chamber and there is a continuous ignition means, these being preferably one or more glow plugs. Assuming the engine to be in operation, an explosion in the left combustion chamber drives the piston to the right. Air on the right side of the right compressor is forced to the left side of the compressor piston and to some extent into the right combustion chamber. Air in the left compressor at the same time is being forced into the left combustion chamber to scavenge burned gases. As pressure builds up in the right combustion chamber, the charge ignites and drives the piston in the opposite direction until the exhaust ports are uncovered, at which time an explosion occurs in the left combustion chamber.

The walls of the cylinder 2, especially about the combustion chambers, are provided with heat-dissipating fins 12. I propose to make each combustion head of a diameter to closely fit in the bore of the cylinder and at the place where the heads are to be located the cylinder walls are outwardly thickened, as indicated at 2a. The combustion chamber heads are each provided with a resilient expansion ring 15 that is compressed into a peripheral groove 16 in the head as the head is pushed into place. When the head is in proper position the ring expands into an annular groove 17 in the thickened part of the cylinder wall to lock the head in place. To remove the head there are provided several, preferably four, equally placed machine screws 18, that can be screwed in to compress the locking ring back into the groove in the head. The head may have other piston rings 19 on its periphery to form a gas-tight seal.

Each head carries one or more ignition devices. I prefor to provide four conventional hot wire glow plugs 20 equally located about the center of the head in the face which confronts the cylinder. One terminal of these plugs is connected to an asbestos insulated wire that extends outwardly through the cylinder wall. There is a single fuel injection nozzle 21 having a tiny orifice in its discharge end screwed into each end and supplied with 3 I l 7 fuel through a radial opening that registers with a fuel supply pipe 22 screwed into the cylinder casing. Fuel is continuously injected under moderate pressure.

The combustion head also has an air passage 23 therethrough each of the combustion heads and has a reduced terminal at each end on which is secured the air piston 6 held in place by a nut 6a. These air pistons have piston rings in their peripheries. therein which opens toward the nearest combustion head, and which may be similar to the ones in the combustion heads, but which are preferably spring-biased to delay opening, and the expansion of residual air under heat keep some pressure in this chamiber so that on itsoutward stroke a vacuum sufficient to overcome the spring is not immediately formed.

The compressor cylinder heads 7 may be secured in place by an expansion ring 7a similar to the manner in which'the combustion cylinder heads are held in place,

Each has a check valve 10 Because of the thrust that the exhaust gases generate, and the light weight of' the engine, it is contemplated that the engine may be used not only for small boat propulsion, but they may be used on the ends of the helicopter vanes, or on small aircraft, and elsewhere. If desired, the piston rod may be extended through one end of the cylinder and'compressor, as shown in FIG. 6, where 55 machine screws 28 similar to screws 18 being provided 7 c to compress the locking ring when the head is to be removed. The cylinder Wall is similarly thickened at 2b where these rings are located.

Each compressor head has an inwardly-opening check valve 11 therein similar to. the ones in the combustion heads. If so desired, there may be an air induction tube on the outside of the head with a butterfly valve to throttle the flow of air to control engine speed.

There may also be a threaded nipple 31 on-the one and preferably both of the compressor heads with a check valve similar to a pneumatic tire valve therein. To start the engine an air hose from a compressed air tank or tire inflating hose is applied to this nipple. If the piston is in the position shown and air is introduced through this nipple and valve, it drives the piston assembly "toward the left compressing air between the left face of the combustion piston and the confronting combustion head. As this pressure buildsup, the glow plugs ignite the fuel.

Since pressures on opposite sides of the piston tend to equalize, thepiston Will normally. close the exhaust ports when the engine is not operating, so I have shown a valve 31 on one end only of the engine, but it may be duplicated at the other end. W

The piston rod may have an axial bore 50 at one end opening into radial passages 51 in the piston, these passages terminating in piston ring retaining grooves. A check valve 52 allows air to flow axially into the rod and out these radial passages to supply compressed air under the piston rings to increase compression. Lubricant may be introduced into the liquid fuel.

As shown in FIGS. 1, 3 and 6 of the drawings, a

tapering nozzle designated generally as projects laterally from the cylinder 2, the top and bottom walls of this 'nozzlebeing generally'tangential to the cylinder andconverging toward their free end. All of the exhaust ports 8 open into this nozzle. Since the engine operates at several thousand cycles a minute, the volume of gases expelled through thenozzle creates a thrust WhiCh'lS particularly effective in water ,or in air for propelling an object to which the engine is attached through such media. To further increase the volume of these gases, a

plate 41 may be positioned inside the nozzle 40 equidistantly between the side walls thereof and spaced from both the side walls] Water may be sprayed through pipes is the projecting end of the piston rod. It may have a tool 56 attached thereto, such as ,a saw or hammer or chisel, or used to vibrate concrete forms, or to be otherwise used where a vibratory action is required. The stroke is preferably a short stroke so that the reciprocating motion is not usually translated toa rotary motion, but this expedient is not excluded from the field of utility. When used as a vibrator or'to drive a tool the exhaust would be desirably enlarged and discharged into a muffler.

While I have shown and particularly described one embodiment of my invention, it will be understood that this is, by Way of illustration and that various changes and modifications may be made therein, particularly as to details of construction to facilitate manufacture and assembly thereof. a

I claim: 1. An internal combustion engine comprising a cylinder having an exhaust outlet in the periphery thereof between its ends, a cylinder headsealed in the cylinder at each side of the exhaust outlet and spaced equal distances therefrom, a piston having a slidingfit in the cylinder between said cylinder heads, the length of the cylinder between the heads and the axial length ofthe piston being such as to allow the piston to travel in either direction past the exhaust. outlet, a continuously open means for injecting-fuel into the cylinder adjacent each .head, a passage through each head for supplying the entire combustion air for the cylinder adjacent said head, said passage having an inwardly-opening check valve therein, fuel ignittherethrough with an inwardly-opening check valve therein, a piston on each end of said piston rod slidably fitted in the cylinder forming the compressor chamber and movable in their respective compressor chambers with the first- 42 connected to a supply pipe 43 against this plate. The;

'ment the thrust fromthe nozzle 40.

water willbe rapidly converted to steam and thereby auge i;

named piston as it moves, and a passage with an inwardlyopening check valve for the passage of air from the outer end of each compressor chamber to the inner end.

4. An internalcombustion engine as defined in claim 3 in which said last-named passage is through the respective pistons in the compressorchambers.

5. An internal combustion engine as defined in claim 3 in which there is a nipple with an inwardly-opening check valve to which an air hose may be attached for introducing air under pressure into one compression chamber for starting the engine.

6. An engineas defined in claim 1 in which the cylinder heads are removably sealed in the cylinder and the head and piston assembly are removable endwise from the cylinder.

V 7. An internal combustion engine comprising acylinder having. a cylinder head at each end and an exhaust port midway between the two heads, a piston slidably fitted in said cylinder, means for supplying combustion airunder pressure intoeach end of the cylinder, continuously open means for injecting fuel into each'end of the cylinder,

means in each endof the cylinder for igniting the fuel,

and a tapered exhaust nozzle extending radially from the.

from the interior walls thereof about which the exhaust gases sweep, and means for spraying water against said plate for generating steam.

9. An internal combustion engine comprising a cylinder having a cylinder head at each end and an exhaust port midway between the two heads, a piston slidably fitted in said cylinder, a rod on which the piston is fixed having its ends slidably passing through the respective cylinder heads, an air compressing cylinder at each end of the first cylinder, a piston on each end of said rod in each of the air compressing cylinders, check valve means eifective for admitting atmospheric air to the air compressing cylinders upon movement of the respective pistons therein in one direction, check valve means in each cylinder head for passing air from the compression cylinder directly into the adjacent end of the first cylinder, but preventing reverse flow of gases from the first cylinder to the adjoining compression cylinder effective movement of the respective pistons in the air-compressing cylinders in the other direction, said air-compressing cylinders and piston thereby functioning alternately to force air under pressure into opposite ends of the first cylinder, continuously open means for injecting fuel into each end of the first cylinder, and means at each end of the first cylinder for igniting the fuel, said compressor cylinders and piston supplying the entire combustion air for operating the engine.

10. An internal combustion engine as defined in claim 9 wherein said first piston has a grooved periphery with an expansible piston ring therein, the piston rod having a passage leading therethrough from one air-compressing cylinder to the piston, the piston having a radial passage leading from the passage in the rod to said groove for injecting air under pressure against the inner face of the expansible piston ring.

References Cited by the Examiner UNITED STATES PATENTS 1,148,206 7/15 Westinghouse 12365 1,653,373 12/27 Rice l2346 2,168,829 8/39 Pescara 23056 2,398,221 4/46 Gerhardt 6013 X FOREIGN PATENTS 488,477 12/29 Germany. 921,605 12/54 Germany.

27,724 1907 Great Britain. 948 1906 Great Britain. 208,150 10/24 Great Britain. 565,952 12/44 Great Britain.

SAMUEL LEVINE, Primary Examiner. 

7. AN INTERNAL COMBUSTION ENGINE COMPRISING A CYLINDER HAVING A CYLINDER HEAD AT EACH END AND AN EXHAUST PORT MIDWAY BETWEEN THE TWO HEADS, A PISTON SLIDABLY FITTED IN SAID CYLINDER, MEANS FOR SUPPLYING COMBUSTION AIR UNDER PRESSURE INTO EACH END OF THE CYLINDER, CONTINOUSLY OPEN MEANS FOR INJECTING FUEL INTO EACH END OF THE CYLINDER, MEANS IN EACH END OF THE CYLINDER FOR IGNITING THE FUEL, AND A TAPERED EXHAUST NOZZLE EXTENDING RADIALLY FROM THE CYLINDER INTO WHICH THE EXHAUST PORT OPENS. 